Yeah, forget about the new buff system. Summing up, not removed, rewritten (maybe?). But still, the passive nature of wellness its a feature to be expanded, not removed entirely. It can be summarized as chore/stumbling block/whatever, but serious, in a survival game what isn't? If the game have more integration with the system it might make it more interesting and fun to keep up, not the hunting-farming-stew-perk-forget about it.
And about buffs and chores, keep a buff up is a more tedious (and spamming) task than a passive buff rewarding you to staying alive and and eating well - the problem in the game right now is that you simple just not lose wellness enough (and can get it up pretty fast).